1. Field of the Invention
The invention is directed to the dangers and problems presented by certain vehicles which, due to their length, must execute wide turns. Overlength and combination vehicles, such as semi-trailer and tractor units or truck and trailer units, are required to initiate turns from a location in the roadway that it well inside the curb lane of the road. This inherent feature of vehicles of exceptional length poses a grave danger for following traffic. Drivers are incapable of independently and immediately evaluating the length of other vehicles travelling on the road and, as such, are unable to appreciate the serious risk of collision created by turning overlength vehicles. In the United States, and other areas where ongoing traffic is by law required to utilize the right-hand lanes of a roadway, the risk of accident encountered when an overlength vehicle executes a right-hand turn is heightened, especially for traffic following in the curb lane. Thus, the need exists to warn and alert traffic travelling on our roadways of which vehicles are physically required to make wide turns. Such a warning allows other drivers to anticipate and avoid the danger created by overlength, wide-turning vehicles. An even more desperate need exists to not only warn of or identify those vehicles which must make wide turns, but to inform drivers of this fact prior to and simultaneously with the overlength vehicle's initiation of the turn. Following traffic, particularly curb lane traffic, will thereby be informed of the intention of the driver of the overlength vehicle to execute a turn and of the fact that said turn must necessarily be initiated from an interior lane of the roadway. Thus, many of the collisions resulting from the presence of large trucks on the roadways will be entirely prevented and avoided.
2. Description of the Prior Art
At present, many overlength vehicles bear a painted printed warning or a printed sign or decal indicating that the vehicle makes wide turns. This type of warning possesses little value in that it is seldom legible because it is usually covered with road dirt. Furthermore, a printed warning fails to definitively inform other drivers that the overlength vehicle executes wide turns when communication of the warning is most crucial, i.e. prior to and at the moment the overlength vehicle commences its turn. At best, the printed warnings currently utilized communicate to other drivers the fact that the overlength vehicle makes wide turns, but fail to relate the present intention of the vehicle to actually execute such a turn. The prior art also encompasses several patents directed to vehicle indicators or signalling devices. for example, U.S. Pat. No. 2,673,307 discloses a vehicle safety signalling device comprising a casing having multiple compartments within which lamps are disposed. The lamps are interconnected with a switch mounted on the instrument panel of the vehicle. similar vehicle lamps are disclosed in U.S. Pat. Nos. 1,065,444; 1,241,904; 1,650,471 and 2,671,891.
Several prior art patents also show signalling lamps which operate in conjunction with some other vehicle system. U.S. Pat. Nos. 2,276,441 and 2,836,913 disclose vehicle signalling devices operated through the vehicle's brake mechanism. U.S. Pat. No. 3,305,961 shows an illuminated signal adapted to be connected to the cigarette lighter of the vehicle. Finally, U.S. Pat. No. 3,802,103 discloses an advertising display that is illuminated when the ignition circuit of the vehicle is closed.
The prior art fails to disclose a flashing warning which is activated in conjunction with the existing directional turn signal system of the vehicle and which identifies the vehicle as one required to negotiate wide turns as well as indicating the contemplated direction of turning of the vehicle.